Linear structural member



Dec. 4, 1951 J, L, BARRETT 2,577,671

LINEAR STRUCTURAL MEMBER Filed Dec. 5, 1947 r Illlll'."

IN V EN TOR.

c/f/A/ L. 56766577' fw #M Patented Dec. 4, 1951 Application Djeeemter 5,1947;. sentirne. is'gse'i.

This invention"v relates'l to improvements linearMstructu'ra'l membersand'l particularly" toV such a; membern designed for use as" an'l antoemobile' top bow:

Anotherr object iste' provide'a structural"meine ber' of'V this typewhich is" light in" weight, of:

inexpensive` construction;l and* embodies' the" characteristics ofsubstantial" strength" and'Y resistance toundesirable" twisting,warping" or bending;l i

` Anotheroobject is t'oproylde4 'afstr'Uctura'lmem' ber'of` thischaracter"composed oi a pair'oiL cooperating linear` structural Vmemberswhich are so shaped and so' interlocked' together' as to reinforce eachother" and provide a composite structural memberu possessing' thedesiredxr characteristics of strength; light weight', andv cheap'-ness'.`

More" sp'eciiically each oithe* component linearY structural parts whichgoestto makeup the complete structural'memb'er is' oi" a generallychannel' shapeL in transverse cross' section and one such channel-shapedpartdsdisposedwithin'the channel of the other part and" so interlocke'dvtherewith' as4 to` provide a" strong' construction. A desirable featureresidesin the' fact that the one channel-shaped part which' is'disposed' in'- teriorly f of' then otherhas'its sidewalls engaged byinwardly: and downwardlyv turr'i'ejd` marginal'. portionsof theAsidewalls of/ the eizteriorly dis'- posed channel-shaped part" so' that"atensionxv is* exerted between the sidewalls of the'two parts tending tomaintain the interlocked engagement.

The one channel-shaped part which is dis'- posedtinteriorlywithin theother channel-shaped part is, in one embodiment, disposed therein insuch a manner' that the bottoms ofthe two parts rest one uponY anothervand-I the'- side`I walls of the two parts are disposed inspacedfparallel rela-f tionship and themargins of the side? walls of theouter channel-shaped part are inturnedI into interlocled engagement withtheside wall'sof the'. inner channel-shaped-part. On the other hand in`another embodiment the interiorly disposed' channel-shaped part isinverted` within the Vexterior channel-shaped partv whereby the bottomvoffthe interior channel serves toll the space between the interiorlybenty marginalfpcrtions ofthe side walls ofh the outer channel and liesflush therewith-*andA theY margins of the side Vwallsf of; such outerchannel abut the margins ofl the' side walls .of the innerchanneland'l'iold the same in place.

The interlocking engagement of the side walls `of the two channelshapedparts is such that a tension is exertedy there lfetweenv-holdingtlietwcrV channeleshaped parts together.'

OneL particularV embodiment of' this improvedy structure is" in anKMAautomobile"y top bow.V Such" bowshaveheretoiore'been commonlyforriieizlj of' tubes and* 'the tubes bent and formed int'othe desiredshape. My structural member-possessesadvantagesoverthetubularrnemberandjmy improvedbow"possessesadvantages as a'bowirl-tneparticul arY manner`v in which it is` formedL over the well knowntubular?bow'.r

In 'ai prefe'rrediorirrofbow'fabricatedas'hereiri'v setiortli, botnspecifici embodiments or the etnietural" member: are: einpi'oyed. Thetop portion oflmy" improved'bowfemploys the"modifl"cation1 wherein theinteriorly vdispfrsed channel?v meirrl'iier has the" bottom oil itschannel' arranged" witli' margins of" thesi'de wallsoftlie-outer. mem'-v ber; while. the" en'd portibnsof* my improved bows" have the twochannels arranged bottomto'bottoml and" with tli'ev side walls?s'paceor'y apart' butt'marginallyinterloeled andtlieinnercliannelcarries' a tacliing strip.

Various" other objects;` advantages' and" meritorious' features' ci"`the' invention will become more. i fllyj apparent from the'V followingspeeinl caticin',v claims Y andJ accompanying" drawings. wherein:

lig.L 1A is a. perspectiie",of a. fragment sofia cabriol't'body'-sl'owi'ngan automobile top; bow

1n use. Y

Fig. 2`isA acrosssectionalfview taken onvthe' line.. 2--2' of lig.v 1..

Figi 3i i'sia. cross sectional'Y View taken. on tl'ie lihe'3l-3'of1iig.I.

liig.V 4. is. a? cross sectional view through the outer, channel member.Y

ig.v` 5 isla`v cross. sectional view. showing,- oneI method of.inserting thev innerl channelrmember within-the outer channell member..

n In its generalaspects .this .invention .relatestc alinearstructuralmember.k Such.- rrlemberv is shownas madegupl of two linearstructural parts. Thesepartsaare intertted together so--asftorpre` vide.astrong; .light weightgrelatively inexpensive: structuralmemberwhichisadapted to beusedg for different purposes,l A *use presently in` mindlis thatsof;A an automobile top bow' and such ai' bow? is illustratedz asembodying l this invention the drawing, InQthe-:drawingthe bodyin'dicatedas, Hl is-E illustrative of.l thisftypeso'fgarticle andsuch--k bow; lsf-'formed of the composite/:lineair structural:memberzillustratedrin'.Figsi 2 andzi Fig. 1 illustrates a fragment of acabriolet body wherein the body portion is indicated as l2 and isprovided with a top structure wherein the bow I is employed. In thefabrication of this bow I prefer to make use of the two modifications ofthe invention illustrated in Figures 2 and 3. The invention as embodyingthe body structure of Fig. 2 comprises a channel-shaped part indicatedgenerally as I4. This channel-shaped part has a bottom which is convexupwardly as at IB and side walls I8. Each side wall is turned inwardlyas at 20 and then bent downwardly as at 22. The downwardly bent marginsof the two side walls engage cooperating shoulders of the side walls ofan inner channel member.

The inner channel member is shown disposed within the outer member andas having a bottom portion 24 which is convex inwardly to nest over thebottom portion I6 of the outer channel member I4. This inner channelmember has two opposed side walls 26 which are provided with shoulders2B adapted to be engaged by the edges of the downwardly turned margins22 of the side Walls of the outer channel member as shown particularlyin Fig. 2. The construction is such that the side walls of the outermember exert a tension or pressure against the side walls 26 of theinner member so as to maintain the two parts snugly locked together.

In the construction shown in Fig. 3 the outer channel member I4 isformed in the same fashion as shown in Fig. 2 having an interiorlyconvex bottom I6 and upstanding side walls I8 bent downwardly as at 20and provided with downwardly bent marginal portions 22. The innerchannel member is of a construction different from that shown in Fig. 2.This inner channel member has a bottom portion 30 and two side wallportions 32 which side wall portions are curved outwardly so that eachside wall is bent reversely upon itself forming a marginal portion 34provided with a shoulder 36 adapted to be engaged by the downwardly bentmarginal por' tions 22 of the side walls of the outer channel member.This is shown in Figs. 3 and 5. It will be seen that in this structurethe inner channel is inverted and its bottom portion is substantiallyflush with the portions 20 of the side walls of the outer channel memberso that a piece of fabric 35 may be stretched thereacross as shown inFig. 3 and be supported thereby.

The outer channel member is so formed that its side walls are normallyspaced apart a distance such that the downwardly bent marginal portions22 will exert a tension against the marginal portions oi the innerchannel member as they rest upon the shoulders thereof as shownparticularly in Figs. 2 and 3.

In order to assemble the inner channel member the side walls of theouter channel member may be held inwardly as shown in Fig. 5. When heldinwardly by fixtures as here shown the inner channel member may bereadily inserted therebetween. UponV release of the pressure against theside walls of the outer channel member the two members are interlockedtogether under tension. Though in Fig. the modiiied inner channel membershown in Fig. 3 is shown inserted in the outer channel member it isapparent that the inner channel member shown inv Fig. 2 could beinserted therein in the same way.

For a linear structural member either the form shown in Fig. 2 or thatshown in Fig. 3 might be employed. In the fabrication of an automobiletop bow it has been found desirable to employ both modifications. Thebow shown comprises the outer channel member I4 which extends for thefull length of the bow and is provided with suitable end ttings. The endportions of the bow may be formed from the modication shown in Fig. 2. Atacking strip 40 is shown in dotted outline as disposed therin and asshown in Fig. 3. A fabric sheet 35 may be stretched thereover andsecured thereto in any conventional manner. The intermediate or topportion of the bow may be formed of the modication shown in Fig. 3 and abow so formed has been found to be particularly suitable for use.

What I claim is:

1. A linear structural member comprising one linear portion which ischannel shaped in transverse cross section, a second linear portionwhich is channel shaped in transverse cross section and which isdisposed Within the channel of the first portion between the side wallsthereof in inverted relationship with the bottom of the channel shapedsecond portion disposed approximately flush with the upper margins ofthe side walls of the channel of the rst portion and with the side wallsof the second portion curved outwardly upon themselves and backwardlytoward the bottom of the channel and provided with inwardly disposedshoulders, the side walls of the rst portion being bent inwardly towardthe bottom of the second portion and then bent downwardly inside of andinto abutting engagement with the shoulders of the side walls of thesecond portion.

A linear structural member comprising one linear portion which ischannel shaped in transverse cross section, a second linear portionwhich is channel shaped in transverse cross section and which isdisposed within the channel of the first portion between the side wallsthereof ,in inverted relationship with the bottom of the channel shapedsecond portion disposed approximately iush with the uper margins of theside walls of the channel of the rst portion and with the side walls ofthe second portion seating against the bottom of the first portion andthen curved outwardly upon themselves and Vbackwardly toward the bottomof the channel and provided with shoulders facing opposite margins ofthe bottom of the channel and spaced therefrom, the side walls of thefirst portion being bent inwardly toward the bottom of the secondportion and then bent downwardly inside of and into abutting engagementwith the shoulders of the side walls of the second portion and tensionedoutwardly against the shoulders of the side walls of the second portion.

JOHN L. BARRETT.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 364,989 Garmont June 14, 1887686,817 Macphail Nov. 10, 1901 1,113,559 Jordan Oct. 13, 1914 1,217,398Bonnell Feb. 27, 1920 1,347,881 Vetter July 27, 1920 1,668,953 EricksonMay 8, 1928 1,710,205 Clark Apr. 23, 1929 Y FOREIGN PATENTS NumberCountry Date 556,128 Germany Aug. 2, 1932

